Improvement in boiler safety-valves



tinitetl tant @anni l @it EDWARD ANDREWS, l0E' PoTTsvILLE, PENNSYLVANIA.l Letters Patent No. 83,125, dated October 20, 1868; antedated October 9, 1868.

The Schedule referred to in these Letters P atent and making part of the same.

To all whom it may concern Be it known that I, EDWARD ANDREWS, of the borough of Pottsville, in the county of Schuylkill, in the State of Pennsylvania, have invented a new and improved Mode of Allowing the Sur'plus Pressure to Escape from Steam-Boilers; and I do hereby declare that the following is a full, clear, and exact description thereof, reference being had to the accompanying drawings, and to the letters of reference marked thereon. i

lIhe nature of my invention consists in providing steam-boilers with a safety-valve that will allow all the surplus pressure to escape under all circumstances.

Figure 1 is an exterior view complete, showing the voperation of the weights I and Gr.

Figure 2 is a View of the arrangement of the piston K, valves W and E, and operation of the yoke D.

Figure 3 is an interior view, showing the operation.

lof the'valve J lever H, and piston K; also, the openings for the valves` W and E in the column A and the box B.' f

To enable others skilled in the art` to make' and use my invention, I willproceed to describe its construc- `tion and operation.

I construct the column A, 'gs 1 and 3, having the connection to the valve-box B, containing the pressurevalve J and lever H, and being proyided with a cylin- Nder at N, having the piston K to operate in it. Also the Avalve W, opening inward, as shown at iig. 3, by the opening in the box B.

The valve-box B, enclosing the pressure-valve J and. lever H, steam-tight, as shown.

The upper part of the column A being constructed withtwo valve-seats opposite eachother, one opening inward andthe other outward, thus presenting an equal surface for the steam to operate upon, and fitted with the double valve E. The pressure being equal on the valve to open or close, it forms a balance-valve.

The end of lever H, g. 3, operating on piston K, and it being connected to the yoke D, which is also connected to the angle-lever C, having the weight G upon it, allows the pressure to be regulated on the valve J The balanced valve E is connected to the lever F, to allow it to be regulated by the weight I, if found necessary, on account of the larger surface of the valve E being exposed to the pressure when open, and' also to c ose it when released by the yoke D.

he valve W, in the bo'x B, iig. 1, being provided with the stem, slipping through an yaperture in the 'cross-piece ofthe yoke D, having the set-nuts to regulate it, as shown at fig. 2, the set-nuts l 1 being adjustable on 'the stem oi' the valve W, to control the motion of the piston K, and relieve the pressure in w the box B.

The.operationV is as follows: The column A being secured to the boiler by suitable means, and the steam having free access in the column, acts directly on the valves J and E, and when the pressure on J overcomes the weight on the lever C, the valve J opens, and allows the steam to escape into the box B, and operating on the surface of .the piston K, overcomes the resistance of' the weights G and I, thereby opening the double valve E by the projecting piece, as shown at M, iig. 2 coming against it, thereby allowing' the surplus pressure to escape. The valve W, which has been opened'by the same movement, it being regulated by the set-nuts 1 1, allows the steam to escape from the box B, relieves the piston K, and allows the weight G to close the Valve J, and at the same time releases the valve E, which is closed by the weight, I, operating on the lever F; the valve W being closed by the same movement when the pressure gets -below that required. 4

It will be observed that the motion of the piston is controlled by the set-nuts, and thatthe valve W being moved further than the valve J, by the number of fulcra in the lever H, allows the pressure to escape faster than admitted by the valve J.

Having thus fully described my invention,

W'h'at I desire to secure by Letters 1)L tent, is-

1. The arrangement and combination of the balanced valve E with the valve J, lever H, piston K, and yoke D. "f

2. rPhe arrangement of the box B, enclosing the valves J and W, and levc'r H.

, EDWARD ANDREWS.

Witnesses: 4

JNO. M. MILLER, CHARLES SPENCER. 

